docs: def add_tagged_report_number(reading_line,
                               len_reportnum,
                               reportnum,
                               startpos,
                               true_replacement_index,
                               extras):
      """In rebuilding the line, add an identified institutional REPORT-NUMBER
         (standardised and tagged) into the line.
         @param reading_line: (string) The reference line before capitalization
          was performed, and before REPORT-NUMBERs and TITLEs were stipped out.
         @param len_reportnum: (integer) the length of the matched REPORT-NUMBER.
         @param reportnum: (string) the replacement text for the matched
          REPORT-NUMBER.
         @param startpos: (integer) the pointer to the next position in the
          reading-line from which to start rebuilding.
         @param true_replacement_index: (integer) the replacement index of the
          matched REPORT-NUMBER in the reading-line, with stripped punctuation
          and whitespace accounted for.
         @param extras: (integer) extras to be added into the replacement index.
         @return: (tuple) containing a string (the rebuilt line segment) and an
          integer (the next 'startpos' in the reading-line).
      """
      rebuilt_line = u""  # The segment of the line that's being rebuilt to
      # include the tagged & standardised REPORT-NUMBER
  
      # Fill rebuilt_line with the contents of the reading_line up to the point
      # of the institutional REPORT-NUMBER. However, stop 1 character before the
      # replacement index of this REPORT-NUMBER to allow for removal of braces,
      # if necessary:
      if (true_replacement_index - startpos - 1) >= 0:
          rebuilt_line += reading_line[startpos:true_replacement_index - 1]
      else:
          rebuilt_line += reading_line[startpos:true_replacement_index]
  
      # Add the tagged REPORT-NUMBER into the rebuilt-line segment:
      rebuilt_line += u"<cds.REPORTNUMBER>%(reportnum)s</cds.REPORTNUMBER>" \
                      % {'reportnum': reportnum}
  
      # Move the pointer in the reading-line past the current match:
      startpos = true_replacement_index + len_reportnum + extras
  
      # Move past closing brace for report number (if there was one):
      try:
          if reading_line[startpos] in (u"]", u")"):
              startpos += 1
      except IndexError:
          # moved past end of line - ignore
          pass
  
      # return the rebuilt-line segment and the pointer to the next position in
      # the reading-line from  which to start rebuilding up to the next match:
      return rebuilt_line, startpos